20221545 has 16 divisors (see below), whose sum is σ = 32448960. Its totient is φ = 10753344.

The previous prime is 20221541. The next prime is 20221547. The reversal of 20221545 is 54512202.

It is a happy number.

It is not a de Polignac number, because 20221545 - 2² = 20221541 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20221541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3907 + ... + 7463.

It is an arithmetic number, because the mean of its divisors is an integer number (2028060).

Almost surely, 2^20221545 is an apocalyptic number.

It is an amenable number.

20221545 is a deficient number, since it is larger than the sum of its proper divisors (12227415).

20221545 is a wasteful number, since it uses less digits than its factorization.

20221545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3944.

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 20221545 is about 4496.8372218705. The cubic root of 20221545 is about 272.4403595315.

Adding to 20221545 its reverse (54512202), we get a palindrome (74733747).

The spelling of 20221545 in words is "twenty million, two hundred twenty-one thousand, five hundred forty-five".